POST UTME GREENFIELD UNIVERSITY 2021 Chemistry | Objective

Practice these randomly selected questions to test your readiness.

Question 1
The diagram below shows a setup for the electrolysis of water. What is the purpose of the U-tube?
A. To measure the volume of the electrolyte
B. To collect the hydrogen gas
C. To prevent the electrolyte from overflowing
D. To measure the temperature of the electrolyte
Question 2
A solution contains 0.05 M HCl. If 20 mL of this solution is added to 100 mL of 0.1 M NaOH, what is the concentration of the excess reac\tant?
A. 0.01 M
B. 0.05 M
C. 0.1 M
D. 0.2 M
Question 3
Determine the rate cons\tant (k) for the reaction: A → B + C, given that the initial concentration of A is 0.5 M, and after 20 minutes, the concentration of A has decreased to 0.2 M. The rate cons\tant is related to the half-life \( t1/2 \) by the equation: k = ln(2) / t1/2.
A. 0.05 min^-1
B. 0.1 min^-1
C. 0.2 min^-1
D. 0.5 min^-1
Question 4
Determine the number of moles of electrons transferred during the electrolysis of 2.5 L of 0.5 M H2SO4.
A. 1.25 mol
B. 2.5 mol
C. 5.0 mol
D. 6.25 mol
Question 5
A 2.0 g sample of a polymer is dissolved in 100 mL of water. Calculate the concentration of the solution in g/L.
A. 20 g/L
B. 40 g/L
C. 60 g/L
D. 80 g/L
Question 6
A solution contains 0.1 M NaCl. If 10 mL of this solution is diluted to 100 mL, what is the concentration of Na+ ions in the final solution?
A. 0.01 M
B. 0.05 M
C. 0.1 M
D. 0.2 M
Question 7
A solution contains 0.1 M CuSO4. If 25 mL of this solution is diluted to 100 mL, what is the new concentration?
A. 0.01 M
B. 0.05 M
C. 0.1 M
D. 0.2 M
Question 8
A 2.0 L flask contains 0.5 mol of CO2 at 25°C. What is the partial pressure of CO2 in the flask?
A. 0.5 atm
B. 1.0 atm
C. 1.5 atm
D. 2.0 atm
Question 9
A 0.1 M solution of H2SO4 is titrated with 0.1 M NaOH. Calculate the pH of the solution after 25 mL of NaOH has been added.
A. 1
B. 2
C. 3
D. 4
Question 10
A polymer has a molecular weight of 100,000 g/mol and a degree of polymerization (DP) of 500. Calculate the molar mass of the repeating unit of the polymer.
A. 200 g/mol
B. 500 g/mol
C. 1000 g/mol
D. 2000 g/mol
Question 11
The half-life of 14C is 5730 years. If a sample contains 50% of the original amount of 14C, how many years have passed?
A. 1000 years
B. 2000 years
C. 5730 years
D. 11460 years
Question 12
A diagram of a redox reaction is shown below. What is the oxidation state of the underlined atom?
A. +2
B. -2
C. +1
D. -1
Question 13
The s\tandard enthalpy of formation of CaO(s) is -635.09 kJ/mol. Calculate the s\tandard enthalpy of formation of CaCO3(s) from the following data: ΔHf(CO2(g)) = -393.51 kJ/mol, ΔHf(C(s)) = 0 kJ/mol.
A. -1206.60 kJ/mol
B. -1206.60 kJ/mol
C. -1206.60 kJ/mol
D. -1206.60 kJ/mol
Question 14
A gas at 25°C and 1 atm is compressed to 2 atm. What is the new volume of the gas?
A. 0.5 L
B. 1 L
C. 2 L
D. 4 L
Question 15
Determine the oxidation state of the underlined atom in the compound [Cr\( H_2O \)_5Cl]Cl_2.
A. +3
B. +2
C. +1
D. +6

Master the Exam!

You've seen a preview, but there are thousands more questions plus AI tutor to break down complex solutions.

Unlock Full Access Available for Android & Windows
Help others prepare! Share this practice hub: